Recruit to Food in Pavement Ant Foraging

Presenter(s)

Emily Warsavage

Abstract or Description

Ants, like other social insects, display complex collective behavior in the absence of designated decision-making leaders. Instead, individual ants follow certain behavioral rules, and their actions then guide the behavior of the colony as a whole. Agent-based modeling approaches the study of systems from the level of individual agents, who carry out a set of rules, so it is well-suited for exploring the process of how collective decision making arises from individual interactions with other organisms and the environment. A primary example of complex ant behavior is food foraging, in which individual forager ants search for food in their environment, then signal the discovery of the food to other nestmates by returning to the nest and laying down a pheromone trail, which directs the efforts of the rest of the foragers toward that food source. During this process, the behavior of both the initial scouting ant and its nestmates is shaped by food quality. Initially, in some species, small groups of foragers that are recruited from the nest follow the scouts to the food in orderly lines, in a stage termed group-recruitment. Eventually, as increasing numbers of foragers are recruited, the groups spill into a teeming mass of ants traversing the pheromone trail between the food and the nest, in mass-recruitment. I used the Netlogo modeling program to explore the process of recruitment to food in Tetramorium immigrans (pavement ants), the most common ant in the Denver metro area. T. immigrans thrive in an urban ecological niche, in part due to their ability to outcompete other species for food. The model examines how foraging ants interact with each other and their environment to make the individual decisions that trigger a collective response by the colony to a food source, and the likely moderation of the process by food quality.